Basic Definitions

Components

Saws are comprised of several key elements, a handle1 for driving 1 Sometimes, but infrequently refered to and controling the , a saw-plate which makes up the bulk of the as a tote. saw with the teeth cut into it, and on smaller saws a back which encloses the top of the saw-plate stiffening the blade. The portion of the saw-plate nearest the handle is refered to as the heel, and the opposite end the toe, along the bottom of the plate is the toothline; along the toothline, each tooth has a portion of empty space forwards of it, refered to as the gullet. When sawing, the gap left behind by the saw is refered to as the saw’s kerf, the saw is designed such that it cuts a kerf wider than it’s plate, acomplished by a combination of grinding an almost imper- ceptably slight taper to the blade and setting the teeth such that they splay out slightly from the centreline of the plate.

Geometry

The tooth geometry will vary between individual saws depedning on their exact purpose, the geometry is defined by 3 paremeters. Rake, the angle of the cutting face of the tooth relative to a line vertically perpendicular to the toothline, with a negative angle equat- ing to a slope towards the heel of the saw i.e. 0° would be perpendic- ular to the tooth line, and -10° would slope slightly toward the heel of the saw. Increasing rake increases the agressiveness of the saws cutting action, but for the same reason also increases the force re- quired to push the saw throught he cut and the difficulty in starting the saw off. Fleam, the horizontal angle of the cutting face of the tooth and the back face of the tooth in front relative to a line horizontally perpen- dicular to the toothline, generally speaking the angle of the fleam is 2

expressed as being a number of degrees, when it means a number of degrees ± i.e. a 10° fleam angle would have the cutting face of one tooth angled +10° past perpendicular, and the next face angled -10° just shy of perpendicular. Fleam increases the abillity of the saw to sever individual fibres cleanly by forming knife points, and is essential to the function of cross-cut saws. Slope, the vertical angle of the cutting face relative to a line hor- izontally perpendicular to the toothline. Increasing the slope angle increases the keenness of the cutting edge on teeth with fleam2, and 2 Without fleam, cutting slope will maximises the amount of gullet space available for . Increas- have no effect on the saw other than to reduce the tooth area available to ing slope can also lead to a rougher cut edge, as it’s postive proper- cut at the very tip, and as with fleam, ties allow the saw to cut more rapidly taking the maximum amount the slope angle needs to be opposed on each successive tooth to have the of material per tooth with each pass. desired effect. Filing slope all at one Set, the width of the cutting edge at the outermost extent of the angle would instead cause the teeth to be higher at one side of the toothline teeth, formed by bending the teeth outward slightly. This is usually than the other. set arbritrarily using a saw-set which will have a reccomended set for a given number of teeth per inch, and adjusted by experience to suit individual saws and users. 3 3 It is essential that the saw be evenly set on both sides or it will tend to cut Pitch, is the spacing of the teeth, measured in the number of Teeth toward the side with less set rather than Per Inch (TPI, British practice) or the number of Points Per Inch (PPI, cutting a straight line. North American practice)4. Tooth spacing is important primeraly in To understand this, consider how the plate will align itself if one side is determining how deep a cut the saw can effectively make, as more pressed against the wood, and the other teeth results in a smaller gullet, which can hold less of the waste has extra space. As a result of this, the sawyer will material removed by the teeth before it fills up effectively preventing naturally allow the the plate to lean the tooth behind it from cutting further. very slightly into the extra space avail- able in the kerf on the side of the saw When combined into specific filing patterns, these elements dictate with more set, this then points the almost every aspect of the saw’s peformance and behaviour in use. direction of cut very slightly towards the side with less set, and the error is Seperate to the tooth geometry is the alignment of the handle to compounded with each saw stroke, the blade, or hang; this is the angle between a line perpendicular the eventually cutting a curve with a very 5 wide radius. to the back of the handle and the toothline . 4 A saw with few teeth per inch is described as being coarse, and one with many teeth to the inch as fine, refering Filing Pattern to both the appearance of the toothline, and the quality of the cut surface left There are two predominant types of saw tooth, the Rip filed tooth behind. 5 6 Whilst a seemingly trivial detail, the and the Cross Cut filed tooth, these names unsuprisingly enough hang of a saw significantly alters its refer to the intended purposes of each tooth-filing pattern. ergonomics. In a nutshell, a saw with a higher The Rip filing is cut into the plate with little to no rake angle and hang angle, requires you to work from no fleam angle. This filing pattern essentially creates a series of small above the workpiece with your arm which remove full-width chips of wood when working down pointed diagonally downward and conversely, a saw with low hang angle the grain, but which are unable to cleanly sever the fibres of the requires you to drop your elbow. timber when working across the grain. The dropped elbow position allows you to keep your wrist aligned correctly The Cross Cut filing is cut into the plate with a rake which varies (and thus comfortably) through a from very little in fine saws to the theoretical maximum for a saw much longer stroke, putting all the core muscles into the stroke if neccessary; thus it suits a saw with a longer plate. By contrast a high hang angle allows you to comfortably work in a position which puts you above the workpiece looking down at it; thus suiting small saws for making fine accurate cuts for forming joinery. 6 Often refered to as Fleam Cut. 3

which cuts on the push stroke of -30°, with the fleam is cut at a 7° to 15° angle, with each face angled in the opposite direction from perpendicular such that each pair of faces meets at the tip of the saw to form a needle point. The fine points of each tooth act as a knife to cleanly cut the fibres of the timber when working across the grain, but when working along the grain, the gap in the centre between the two sharp edges of the saw’s teeth means that material is less effectively chipped and removed.

Types of Saw

There are a number of possible divisions between the types of saw, fortunately for the most part saws which are differently constructed are also for differing purposes; it is my aim to take you through them in the order that one would progress through them in turning a tree into a finished article.

Rough Cutting Saws

These saws are primeraly for use in the initial process of turn- ing a tree into usable timber. In the main this class of saws has lost most of their signifiance in light increased mechanisation and the ubiquitous proliferation of timber importers and merchants since the 1840’s; prior to this it was common for firms of carpenters or to retain sawyers, timber wagons and teams of horses and to locally fell, saw and season the timber required for upcoming work7. 7 For a more complete overview of the traditional approach to preparing timber, along with a wealth of other information on the development of the Crosscut Saws trades in the late 18th and early 19th century, it is hard to The one and two man crosscut saws are intended for the cutting of reccomend too highly “The Villiage (? ) logs in the round to a given length after felling, sometimes known as ” by Walter Rose, essential reading for anyone interested in tra- a “Farmers Saw”, they share a variety of unique tooth patterns which ditional woodworking, along with the are variations on the normal Cross-Cut filing. The purpose of these working of “ tree” pumps and the millwright’s work. patterns is to provide ample gullet space to accomodate sawdust and (ISBN-13: 978-0854420650) chips whilst cutting through a log which could be as much as 1/3 – ½ the length of the blade at it’s widest point. These saws are simple to use, but require endurance and persis- tence to make best use of; cutting through a substantial log is necces- sarily time consuming. For Bucking smaller logs, a simple X shaped trestle of two logs joined by a and lashed together is usually used, the major limitation being the size of log which can be lifted onto the trestle, 4

rather than the strength of the lashings; Larger logs can be manu- vered using a Peavy or Log Carrier onto a short log with a v-notch chopped into it with an . It is of course essential to raise the log off the ground to avoid damaging the tooth line of the saw by strik- ing it against unexpected hard objects on the ground, not to mention somewhat more ergonomic to work closer to normal standing height.

Frame Saws

The is traditionally used along with a Cant Hook and Wedges by two people working in a saw-pit or on very large sawhorses to cut timber in the round into planks and beams, along with re- sawing squared up Cants into veneers, planks and feather edged boards. Since the industrial revolution it has been almost completely supplanted by the and later the Wide-Band Saw, and is now of note primeraly to historical re-enactors, and a small number of carpenters working on traditional -framed buildings, although even in the hands of the latter it is being supplanted by portible Band-Mills and “Alaskan” Chain-saw Mills. A smaller frame saw of the same design is mentioned in several texts from the 18th century, this smaller design has been the subject of some experimentation in the woodworking press and at the US living museum, Collonial Williamsburg. The conclusions reached during this period of recent experimentation suggest that a small, one man framesaw can be effective at re-sawing unusually wide boards8rapidly for producing sawn veneers and thin stock for draw- 8 It has been a subject of some debate (? ) ers and Panels. It is suggested that to achieve best results the material in the woodworking press whether they were as effective as claimed in for re-sawing should have a kerf established on both edges, for the some quarters. There seems to be a saw to run in these being established with a “kerfing ” which tentative agreement that the frame-saw was most effective with very wide takes the form of a stair-saw with an adustable attached to hold pieces, upto around 16” width for but the blade a consistent distance from the edge of the board. that for boards of less than 8” a coarse toothed ripsaw of conventional design is quicker and easier.

Handsaws

The name handsaw gives itself to both a class of moderately sized one-man saws invaluble in the workshop, and to the largest size of within that class. They are normally defined by having a handle with a slight hang, almost aligned with the toothline and a saw plate which tapers considerably toward the toe, usually the plate will be taper ground progressively thinner towards the tip. 5

Rip Saw

The Rip Saw is generally the largest of the handsaws used in the workshop, with plate lengths between 28” and 30” most common and lengths of upto 36” not unknown, the plates are normally wide for increased rigidity measuring 7½” to 9” at the heel and 3” to 4” at the toe. The saws are unsuprisingly filed in the rip pattern with a rake which is either 0° or very slight for a rapid and agressive cutting action9 and tend to be quite coarsely toothed, with Pitch between 9 It is worthy of note that whilst un- 3½ TPI and 5 TPI usual, with larger saws for rough work sometimes heardof in hand-tools, in wood machin- ing a positive rake is common for many reaching 2 TPI. ripping blades as the design of saw- A feature unique to the Rip Saw is the “Thumb-Hole Grip”, a benches and confers ability to apply the neccessary force without the larger than normal handle with a small hole forward of the main risk of deforming the plate of the saw. handle10. 10 The purpose of this hole is not as often assumed for the thumb or fore- The rip-saw is used for cutting rough stock to near-finished size finger of the dominant hand, but to prior to final dimensioning with the planes, it has in the main been allow the thumb of the non-dominant surplanted in this role by a variety of small circular sawing machines. hand to be inserted and the remainder of the non-dominant hand to grip the However there are a number of reasons that the rip-saw retains rele- top of the handle, effectively bringing vance in the modern woodworkers toolkit: the power of both arms to bear for extended periods of strenious sawing. • For the re-sawing of boards of rare or valuble timbers into thinner stock it is capable of a combination of a greater depth of cut and narrow kerf than most mechanical saws, minimising wastage.

• For cutting small lengths of timber to width, the rip-saw can be used to cut a board held upright in a vice or held down over- hanging the edge of the with a holdfast very rapidly. Usually the time taken to mark, secure and cut the timber by hand is significantly less than the time required to move to the saw- bench, set the guard and fence for the required depth and width of cut, and finally saw the timber. In this way it can help maintain an economy of time when preparing small one-off components.

• When preparing long lengths of timber in a large sectional size, it can be convenient to work along the board with the rip saw in the traditional fashion, kneeling on the board to be cut supported between two saw-horses. Manuvuring yourself and a saw around a long heavy timber is safer and less ungainly than attempting to control such timbers on a workshop sawbench11. 11 In this way it is possible to accom- plish work which would otherwise require the assistance of a properly Half Rip Saw equipped . This said, depending on the amount of timbers to be prepared, your stamina The Half Rip Saw is a smaller version of the Rip saw, measuring and your budget it may still be well 24” to 28” in length and with a plate width not exceeding 8” at the worth a visit to the sawmill, as these kinds of tasks are normally quite heel or 3” at the toe. Pitch is normally finer than the Rip saw, most heavy work for which the fees of a sawmill will seem quite modest when considering the time and effort saved. 6

commonly between 4 TPI and 7 TPI, giving a finer finish. The filing is again in the rip pattern, but more usually with a slight negative rake, in the region of 10°. In the main, the Half Rip comes into its own for ripping small components at the workbench as above, with a more managable size, finer finish and thinner kerf. With this in mind, the half-rip is usually better suited to making cuts in timber less than 1½” in thickness, where the reduced gullet size does not consititute a major disadvantage.

Handsaw

As mentioned above the Handsaw is the largest of the crosscut saws normally used in and joinery work with prepared timber, 12 The plate will normally be no more than 26” in length and with 12 compared to the average Half-Rip saw a width of 5”-7” at the Heel and 2-3” at the toe, Pitch would gener- the Handsaw offers a slightly smaller form factor which smaller people and ally start around 5TPI (as with the half-rip) and extend to around those working primeraly on small 9TPI, with a a negative rake of 10° to 15°. The fleam and slope of the pieces may prefer to use a Rip-filed Handsaw. Thus whilst the traditional filing will vary with the pitch, decreased fleam and increased slope defining factor of a Handsaw is crosscut (around 8° and 30°) will maximise the speed and depth of cut suiting filing, it is not uncommon to find coarse saws, whilst increased fleam and decreased slope (15° and woodworkers with a pair of handsaws, one in each filing. 5°) will result in minimal splintering and surface irregularity suiting finer saws. The primary use of the handsaw is cutting stock, part-finished components and panels13. 13 It is generally best to use a Hard- Point (non resharpenable) saw for cutting manufactured panel products such as Ply, MDF and OSB, the adhe- sives used can be substantially harder than normal timber, resulting in exces- A smaller version of the handsaw, with a plate of 20” to 22” and a sive wear on the teeth of re-sharpenable width of 5-6 inches at the heel and 1¾” to 2” at the toe, saw Pitch saws tempered for use in timber. is normally slightly finer than that of the average handsaw, in the region of 7TPI to 9TPI14and a negative rake around 15°, with finer 14 The Fine Panel Saw, with a finer pitched examples sometimes extending to 20° rake. As the panel pitch in the 9TPI to 11TPI was formerly common, and still has great utility saw is used for cutting to near finished size, the fleam angle tends for woodworkers building larger to be increased and the slope decreased relative to a comparable carcase work from boards of ½” or less thickness, where the intermediate size handsaw, with fleam of upto 30°, and very slight or no slope to the allows reasonable speed of cut, whilst filing pattern. allowing the use of finer pitch and a thinner plate for improved quality of Panels saws are most useful in cutting components to final length, cut, for cutting larger items to finished and in some cases for cutting unusually large joints; generally mark- size. ing the point that one would move from working on saw horses or saw benches, to the workbench.